Hello there!
This would be an example of a(n) idiom.
Saying something "costs an arm and a leg" could mean something is very pricey, or exspensive.
Hope this helps!
~DL
Answer:
Enjoy the moment while you can, don't focus on the time focus on the moment because you only have that then tomorrow comes and it's just another day.
Explanation:
B. This is because it is unclear about whether or not the bag belongs to the anxious patient or the doctor.